The present invention relates to an ink cartridge for use with an ink jet recording apparatus that performs a recording operation by jetting a series of ink droplets onto a recording paper through a nozzle.
Various kinds of ink feeding systems for an ink jet recording apparatus of the aforementioned type have been hitherto proposed and put to practical use.
To facilitate understanding of the present invention, a conventional ink cartridge having a flexible ink bag received therein and a mechanism for installing the ink cartridge will briefly be described below with reference to FIG. 7 and FIG. 8.
The ink cartridge includes an ink bag a, and a tubular ink outlet piece b is integrated with the ink bag a by applying thermal fusion on one of the thermally fused sides (represented by hatched lines), thereby to allow ink in the ink bag a to be conducted to the outside through the ink outlet piece b. To fixedly hold the ink bag a at a predetermined position in a case e, the ink outlet piece b is provided with a pair of flanges c through which holes d are formed. Thus, the ink bag a can be positioned and fixedly received in the case e by fitting a pair of projections f on the front end part of the case e into the holes d. In addition, the ink cartridge includes a cover j which is placed on the opening of the case e. The cover j is integrated with the case e by thermally sealing the peripheral edge of the case e using an ultrasonic welding process.
A holder m having the case e received therein is fixedly mounted on an ink jet recording apparatus (not shown). The holder m includes a pair of frames n on the opposite sides thereof so as to guide slidable insertion of the ink cartridge h composed of the ink bag a and the case e. In addition, the holder m includes a pair of leaf springs p at the innermost end of the frame n. When ribs i on the opposite side walls of the ink cartridge h are engaged with the leaf springs p, the ribs i are fixedly retained by the leaf springs p. At this time, an ink feeding needle g projection from the ink jet recording apparatus is ready to pierce the central part of the ink outlet piece b.
With such construction, the positional relationship between the ink feeding needle g and the opposing pair of frames n, the positional relationship between the leaf springs p and the ribs i and the positional relationship between the case e and the ink outlet piece b are liable to be undesirably disturbed during steps of fitting and assembling. Thus, there is left unsolved a problem that the ink feeding needle g sometimes cannot be correctly located in alignment with the ink outlet piece b.
In addition, if the cover j is removed from the case e, it is difficult as a practical matter to reunite the former with the latter again such as by employing a thermal fusion process. For this reason, the ink cartridge h cannot repeatedly be used. Further, since the ink outlet piece b is secured to the thermally fused surfaces of the ink bag a, there is left unsolved another problem that a certain gap appears between the ink outlet piece b and the thermally fused surfaces.